1. Field of the Invention
The present disclosure generally relates to a resin composition and more particularly to a resin composition meeting the demands and desirable properties of a rigid-flex board and other products.
2. Description of Related Art
Conventional printed circuit boards primarily contain a glass fiber fabric as the base material and therefore have rigid texture and are also known as rigid boards, which have no flexibility. Electronic products made solely of rigid boards, owing to the limited structural configuration, have many limitations in size and shape design of the end products.
To resolve such problems, a flexible material such as a polyimide film (PI film) has been used in the industry as at least a portion of the flexible printed circuit (FPC) board, also known as a flexible board. Flexible boards have the advantages of thinner in size, flexibility and capability of changing shape according to spatial configuration for three-dimensional wiring. However, since flexible boards have the disadvantages of higher costs, difficulty in multilayer PCB processing, low weight bearing capacity and the like, the use of flexible boards alone is still unable to meet the various needs of electronic product design.
Accordingly, a rigid-flex board has been proposed, which combines a flexible board and a rigid board and is therefore also known as a rigid-flex board. It makes use of the rigidity of a rigid board and the flexibility of a flexible board to meet the demands in structural design of various products. Conventionally, the connection between two rigid boards or a rigid board with a flexible board requires a connector and a wire. However, high-density design is rarely achieved due to the bulk size of the connector, and therefore it is later devised to use a low-flow prepreg for bonding a flexible board and a rigid board so as to form the connection between two rigid boards or between a rigid board and a flexible board, thereby saving the space for the connector and alleviating the problems associated to signal transmission attenuation.
From the design and manufacturing perspectives, in order to connect the flexible board and the rigid board while avoiding fouling the etched circuit pattern formed on the flexible board and the rigid board, a prepreg with low flow property is generally required.
However, resin compositions currently available for such prepregs, although satisfying the requirements of low flow in, fail to perform satisfactorily in other properties. For example, the contamination caused by dust loss (e.g. fallen powders) during prepregs processing will lower the yield, and sufficient peel strength between the copper foil and the insulation layer of a laminate at high temperature are difficult to achieve. Therefore, there is a need to propose new solutions.